INFLUENCE OF HEAT-TREATMENT ON THE VOLATILE COMPOUNDS OF MILK

In this work dynamic headspace capillary gas chromatography coupled wi th multivariate statistical techniques was applied to distinguish milk s subjected to different heat treatments (pasteurization, direct ultra high-temperature method, and ''in-bottle'' sterilization). Results wer e obtained by taking into account a reduced, though significant, numbe r of volatile compounds (acetone, 2-butanone, 2-pentanone, 2-heptanone , 3-methylbutanal, pentanal, hexanal, heptanal, dimethyl disulfide, to luene, and limonene). Moreover, the concentration of these volatile co mpounds, especially aldehydes and ketones, provided discriminant infor mation about storage time and storage temperature in both whole and pa rtially skimmed UHT milk. The analytical method was quite simple, rapi d, and reliable and permitted the analysis of a large number of milks to be carried out by using a small volume of sample. This work represe nts an attempt to apply a method, generally used only for research pur poses, to the quality assessment of heat-treated milk.